Citrus Graphic MKII (ORANGE) PCB Attempt

[mydementia]

Hi guys.
I took a crack at a 1:1 PCB/perf layout of Paul Nelson's Citrus Graphic MKII (ORANGE) preamp sim schematic.  I used bancika's DIY Layout tool and linked the 'project' on my site below (it's in an excel document - wanted to make the off-board connections more clear).  My goal was to fit this sim on the small RadioShack/Smallbear perf board (I still don't make my own PCB's yet - but might if this one works!). 

I've been over the layout several times and would appreciate extra eyes/opinions. 
http://www.freewebs.com/mydementia/DIY%5FStompboxes/ORANGE/OrangeMKII%5Fmydementia.xls

Laying out this circuit from scratch has given me new respect for all you guys who can lay out PCB's with all the I/O on the outer edge... Mine is going to look like a party popper with all the wires coming our of the board! 

I also learned a lot about bancika's DIY Layout tool too...
1) It doesn't like circuits of this size.  Towards the end of the layout, everything I did pegged my processor and had a substantial delay.
2) Moving 'all' (using CTRL-A) doesn't work (thus, my layout is down 2 rows).  It would be nice if the user could adjust the board after the layout is complete.
3) It would be nice if the text was more mobile.  As you can see, it's difficult to make out text over the Pads, etc.

I'll post these issues in bancika's thread too - just thought I'd share.

I'll probably have a go at this today or tomorrow - so your input will be greatly appreciated.  I'd hate to build something that obviously isn't going to work.
Thanks for looking.
Mike

[mydementia]

UPDATE:
I put one of these together tonight - now I get to build a signal injector...

First mistake is that I don't think I did the schematic to layout interpretation for the JFETs correctly:

...so I twisted the source and gate around on all my JFETS...still won't bias.
I get no sound - but the master volume pot gives more or less hiss (wired backwards - shocking).

I'm giving up for the evening.  I'd appreciate anyone's input.

MartyMart - from your build report, I remember you put in a 470nF cap in place of the 6-Pole switch - where did you come up with this value?  If I look at the first position in the schem - I see a coupled capacitance of 11.83nF...what am I doing wrong?

Oh yeah - this is my first build (in 30 or so) that I warmed up a pot (gain) to the point of stinking quite a bit - oops.  I rechecked for solder tails and replaced the pot - no more stink but...

[mydementia]

I'm back at it today (we got a new dog this weekend - not sleeping much anyway!).
I went back through the schem and noticed that C7 is supposed to be 0.01uF - not 0.1uF.  I replaced it and fixed it in the layout but I still can't get any of the JFETs to bias... The trimmers have a lot of control between 0.4V and 1V but then jump to 9V.  VERY difficult to 'dial' in anywhere near 4.5V... something is definitely wrong!
Here's the updated layout:
<<IMAGE REMOVED>>
Here are a couple shots of the circuit - not sure if it's helpful in troubleshooting but maybe there's something obvious that jumps out at you.
<<IMAGE REMOVED>>

Any help/recommendations would be GREATLY appreciated. 
Mike

[Johan]

check the pinout of the FET's.
the reference picture of the FET on the bottom of the layout suggest you have swaped the gates and sources throughout the build...that could be why it doesnt work.
johan

[mydementia]

Thanks for the reply - but I addressed this in my second post. 
Yes - I mis-interpreted the schem to layout for the J201's so I twisted around the source and gate on all four trannies. 
I'm still learning!!!

Any more insight guys?
Mike

[Johan]

Thanks for the reply - but I addressed this in my second post. 

Mike

...oh..sorry..   should have read more carefully....johan

[MartyMart]

From your photo it looks to me that the J201's are totally reversed !
Flat side "left" Drain is at the top, you have the drain at the bottom ....
So reversing gate/source wont help at all

MM.

[mydementia]

Geez - I didn't even get the thing I thought I knew right!!  This layout stuff is hard!!  Thanks for the comment.

Unfortunately, after putting new ones in (Drain on top) with the source and gate swapped around - it still didn't work.  I was able to easily biase Q1, Q2, and Q4...Q3 behaves the same as before... Still no output.

I'm going to put this one down for a few days... I'd still appreciate any thoughts/ideas.

Thanks!
Mike

[MartyMart]

R13 needs to connect to the far side of C14, after Q4 drain
You have that directly connected to Q4's drain .... this is puting a current through that
section of the circuit.
That will be most of your problem around Q3/Q4

From Q2, I ended up with the 0.68 cap then I used a socket for various changes to the "FAG" cap value
I settled on a 10nf, the 470n was just a wild guess !

MM.

[mydementia]

MartyMart - so is the schematic wrong - or am I making another reading mistake?
<<IMAGE REMOVED>>

I socketed the FAC junction too...once I get singnal passing through this beastie - I'll play around with what I like best...
Mike

[MartyMart]

Yeah, it's different from my MKII schematic, mine has the connection after the 0.68 cap !!
as you have indicated ...
I built mine from that schem and it's working perfectly
There must have been an updated schem after ypou downloaded yours

peace,
Marty.

[mydementia]

Aha!
Now I can't wait to get home and try this out...9 more hours...

It's strange, because the two schematics in this thread:
http://www.diystompboxes.com/smfforum/index.php?topic=40353.0
show the same thing that I posted.  Maybe you got a 'special' schem!  Could you put the schem you used up somewhere?  Also, did Nelson answer your last post regarding the 0.22 vs 0.022uF cap?

Thanks for your help!
Mike

[MartyMart]

OK, I notice one other change, cap off the "boost" pot is 0.47uf on the later one too, NOT 10uf !
I skipped the pot anyway and used just one 2k2 resistor and a .47uf cap, instead of the pot & 1k5.
Both off Q3's Gate

MM.

[pbrommer]

I believe I have the same one that MartyMart has. I definately see a difference. I think this is what you need:



Good luck.

Patrick

[nelson]

I believe I have the same one that MartyMart has. I definately see a difference. I think this is what you need:



Good luck.

Patrick

No one cared to ask me for a PCB?

I also recommend just using a 0.68ú cap in place of the FAC rotary. Just omit the FAC.

[mydementia]

Hey Nelson - I asked!!
You gave me a link to your stereo pre-amp layout that didn't exacly match the schematic I was referencing (apparently, I haven't had the right schem until right now!!).  I'm not good enough at this stuff to know what was different for your application and what I needed for a stand-alone stomper. 
I'm going to try tweaking my build to this late-breaking (for me) schematic...stay tuned....
Mike

[mydementia]

OK - now we're getting somewhere.
I made the recommended changes and finally get output!! 
Of course - I had every single pot wired backwards (fixed that too).
I had a bad trimmer on Q3 - now everything biases - hooray!  I'm getting a decent overall tone (with a 0.68uF cap in the FAC section) but the output volume is pretty low.  I think this will be an awesome old Sabbath-esque/Queens of the Stoneage (I know - two ends of the spectrum - that that's how it's striking me) stomper. 

Any thoughts on getting past this last hurdle?
Mike

[mydementia]

UPDATED - Good tone - Low output volume...LAST HURDLE!!

[nelson]

Please dont include my artwork in one picture with your own.

[Seljer]

I'm pretty sure you could stretch out a bit R13 so it can pass over all those traces so you don't need that jumper